Neural crest cells migrate extensively in the embryo along pathways lined with extracellular matrix (ECM) molecules. The long term goals of this proposal are to elucidate the role of interactions between the cell surface and the ECM in neural crest cell migration, localization and differentiation. The proposed experiments will utilize a variety of techniques to investigate cell-ECM interactions both in situ and in vitro. The normal migration of neural crest cells will be perturbed using an injection technique to introduce antibodies and other reagents onto neural crest pathways. The effects of antibodies on neural crest cell adhesion will also be explored on defined tissue culture substrates. After identifying function-perturbing antibodies, we will characterize the antigens immunocytochemically and biochemically on the neural crest cell surface or in the extracellular matrix of the early chicken embryo. The proposed experiments will explore: 1. the effects on neural crest migration of immunologically or biochemically disrupting the ECM lining neural crest routes; 2. the distribution and developmental regulation of various cell surface and ECM molecules in localization along neural crest pathways; and 3. the characteristics of neural crest cell surface antigens which play a role in their migration.